Color Complements With Light or Pigments

May 11, 2011

I might have labeled this “Color Theory for Dummies,” but that title is likely already taken and sounds too insulting anyway. The point of this post is a very simplified introduction to what I know about color theory as it pertains to painting realistically. This involves the translation of colors of light into paint. In this particular post I’m going to try and show the reaction of opposite colors of light and pigments of those same colors when mixed together.

First, let’s try and recreate what happens when opposite channels of light are combined. Since digital files are made with light elements (pixels) they can accurately represent this effect, so for this example I’ll be using the Photoshop program. Color opposites, or “complements,” will be represented in the example above with a familiar artist’s color wheel arrangement of yellow at the top going clockwise through cyan, and magenta, as shown in the top left corner of this Photoshop screen. The center spokes of this wheel show the connections of these colors.

In the center is another file made up of Photoshop layers with four color complements at each corner. The center layer is a duplicate of the cyan color with its display mode set to “normal” and its opacity at 50%. The result shows a gray shade that occurs when the cyan is “mixed” optically with the red-yellow color. If I change the display mode of this layer to “screen” at a 100% opacity, the result is white, since white is all the colors of light combined.

Okay, well, that’s interesting enough, however, it doesn’t always represent what happens when we mix pigments together, since pigments do not behave by the same rules. If you mix red and green lights together you’ll get yellow, but that’s not what happens if you mix red and green pigments. Mix any of the color opposites together, such as yellow and blue, and you’ll definitely not get white. We can, however, create shades of gray when mixing pigments, but even that will take some experience and understanding of how they work together.

As artists we have to account not only for a pigment’s color characteristics (hue, saturation, and value) but also its physical properties, such as its degree of transparency and tinting strength. The color range of what we see is also much greater than what we can recreate with pigments. No matter how opaque is the white pigment you choose, for example, a white pigment won’t blind you. Also, there is no single cyan pigment on the planet. The good news is you can get fairly close, and with some occasional “slight of hand” tricks and balancing of other pigments you can create a convincing facsimile of the colors of light that you see.

In my paint swatch sample here I’m first mixing as close a match to the red-orange as I can get with the pigments I have available (I’m using oils.) I start with the lightest value pigment first, in this case cadmium yellow deep (PO43) and add a small amount of a strong tinting red pigment (PR188) to intensify the hue without darkening it too much. To create the cyan, I choose PY3 yellow tinted with titanium white, and gradually add a mix of blues in the green shade (PB15 & 16.) I occasionally check my progress by holding up the swatch to the screen to see how close I’m getting. I know I won’t be getting the same color intensity as I see on the screen, but that’s okay. In life, unless I’m looking at a light source, all colors I see will be fairly neutral as well and affected by their surrounding colors.

Now for the big reveal, I combine my mixtures of red-orange paint with the handmade cyan in equal amounts and the result has the makings of being a fairly decent shade of gray that I can tweak to be more “warm” or “cool” or as neutral as as necessary.

Even though pigments behave differently than light, it’s important to understand light also. It is, after all, what we are seeing. If you’re trying to translate a foreign language, it’s not just a string of words. You have to know what is being said.